1. Field of the Invention
The present invention relates generally to toner cartridge consuming products such as printers, and more particularly to an apparatus and method for identifying a printer""s toner cartridge using a series of magnetic couplings to generate a cartridge specific identification code.
2. Description of Related Art
The use of toner in paper processing machines to transfer text or images onto stock paper is now commonplace. In many cases toner is delivered via a cartridge specifically designed for the particular machine. Toner cartridges are used in copying machines, stand alone printers, facsimile machines, and a wide assortment of machines designed to process stock or blank paper into paper with print, images, text, or graphics. The methodology behind the particular printing technology is not necessary for an understanding of the present invention and will be omitted for simplicity.
The manufacture of toner using equipment are concerned about the use of the equipment after its initial sale because the manufacture is typically obligated to repair the equipment under warranty agreements. If the equipment can be used improperly, it is often the manufacture who bears the burden of increased costs associated with the misuse of the equipment. One of the main issues that confront these manufacturers is the use of toner cartridges that are not specifically designed for the particular application. The use of some toner cartridges will damage the equipment and cause undo wear and other difficulties.
The problem persists because most varieties of toner cartridge use an interchangeable cartridge design. Many printers include settings optimized for a specific toner cartridge brand or type based on specifications, testing, or experience of the cartridge""s manufacture. The use of interchangeable cartridges leads to the printer""s misinterpretation of the contents of the cartridge, with corresponding misapplied settings specifically adapted for a special cartridge""s characteristics. The result is a poor quality print product and potential damage to the printer. This results in significant costs to the party responsible for maintenance, which must continually repair the toner consuming machines due to the use of non-approved toner, and must answer to questions of poor printer quality.
The present invention is a method and apparatus for identifying a type of printer cartridge to the printer, where magnetic elements on the cartridge and the printer combine to form a magnetic coupling that generates a cartridge specific code to identify the toner cartridge as being of a predetermined type. In a preferred embodiment, the magnetic coupling is achieved using one or more reed switches preferably mounted on the printer (although the switches could be mounted on the cartridge with similar results), with the reed switches biased using fixed magnetic elements placed immediately adjacent the reed switches. In the absence of any further magnetic fields, the reed switches are selected to provide a known set of switch positions corresponding to a bit value of one (xe2x80x9c1xe2x80x9d) for an open circuit and a bit value of zero (xe2x80x9c0xe2x80x9d) for a closed circuit. Magnetic elements on a printer cartridge are positioned to be disposed adjacent the reed switches and opposite the fixed magnets, and of a size and field strength sufficient to counteract the fixed magnetic elements adjacent the reed switches when the cartridge is inserted into the printer. By detecting the status of the reed switches on the printer as xe2x80x9copenxe2x80x9d or xe2x80x9cclosed,xe2x80x9d a sequence of bits of xe2x80x9c1xe2x80x9ds and xe2x80x9c0xe2x80x9ds can be achieved. This data can be used to distinguish one printer cartridge from another and allow automatic optimization of the printer settings based on the cartridge recognition.